Clip-on fuse indicator



Dem 27 1949 w. c. LINTQN CLIP-ON FUSE INDICATOR Filed 0013. 21, 1948 atented Dec. 27, 1949 'UNIT ED i'fSTAT-ES Q FFICE. 2,492,302 CLIP-.ON FUSE INDICATOR William. LintongWashington, D..,C. Vimplication-October 21, 1948, Serial'NoslSTfI (Cl. .200er-.131?) 2 f Claims.

'The presen-t invention relates to lamp ttype indicators yfor all standard cartridge type enclosedelectrical fuses andan .object of .the in,- ventionis to provideaclipfon mounting whereby aniindicator'maybeiretained upon a cartridge type enclosed fuseand .yetzbe movable to various positions .with respect :toithe fuse casing as requirement or conditions may dictate.

Another object of :the-:invention is to provide ahousing:forllampztypefindicators of aznew and novel construction-in which vthe several parts thereof ymay ybe economicallyy constructed and assembled ffor .reducing 'the costs to manufacture and thereby :render r.theeame commercially desirable.

Other objectswillbe in fpart obvious and in part pointedout hereinafter as the description continues.

'ln :the accompanying Ardrawings:

`:F.ig. i1 'is a eide elevationfof 'the iindicator embodying Lthe :presentciiwention'fas :applied to .a standard 'ferruleftype cartridge enclosed fuse.

Fig. i2 :is :aneud :elevation L of the same.

FigJSfis-:anend elcvationof-a cartridge ferrule typefuse mountedin itsv retaining Vclips with vthe indicator mounted along one side thereof.

Fig. '4 is -a-standardknife-blade type cartridge fuse with the indicator applied thereto.

Fig. 5 `is an endelevation of f thev same.

Fig. 6 is .a .Vertical'longitudinal Asectional View through the detached indicator.

rvFig. T'7 is a n'transverse ysection taken yon the line 1 -'Tof 'Fig. .6 inthe-direction of the'arrow points.

Fig. 8 is another transverse section ytaken on the-linel-B--S ofFig. -6"n the direction of the arrow points. y

Fig. 9 is stillanother transverse section taken on the line-.9.-19tof1ig Gein-,the direction of the arrow points.

Fig. isahottom plan .View of theconnecting tube, and

Fig. .'11 is a bottom plan-vlew of an end capof the indicator housing.

vThe indicator. ...as ,herein `shown comprises :a miniaturerneonglow .lamp AI I,having connected in f series itherewith. a ,resistor 2 rwhich when con.- nected in series with the terminals of a fuse, but in parallel with the fusible element thereof will give off a visible signal as to the blown or ruptured condition of the fusible element.

The housing for this la-rnp indicator comprises a sectional casing constructed from a pair of cylindrical end-caps 3 connected together by means of a translucent tube 4 whereby rays of light fr omrthe :lamp l #may ,passzther ethrough and emit therefrom. llhe; end. caps 1,3.are1preferably1molded from` anopaqueiinsulating `material andy are iden.- tical in design A:and construction; The tube '.4 is preferably extruded 'from a :translucent .insulating material .haring the :same external z.diameter aszthatof the endcaps 3. Eachendcapyhasapair of recesses 5 :and eiformed therein .establishing an end wall 1 .and fthe opposite .opened end I.of each cap is provided :with a Areduced annular flange f8 :capable .I of -.extending 4.within :the .opened ends offtheftubef. ,irirascrewsi zextendzthrough tnecpenings J o :formed withinfthe opposite ends of .the :tube: 4 andthe fopenings all of the flanges Stofithe end caps .forrigidly connecting -fthegsame together v.whereby .fthelamp I ,-may be :housed within the .tube Maand one Areduced y.end thereof extending within a recess 5 of an end cap. The resistor 12, may .be positioned within fthe .recess 5 of itheother .end :cap having one lead Wire. l2 connected' :to 4a drivey screw il- :whereas the other lead .wire IAQ-cf the alam-pus .connected to another drive screwil. "lhese,.-drve .screws I3 and L5 extend through openings :L6 formed .in the end caps with their innerrends projecting .withinzthe recesses 16 whereupon ,the lead wires l2 and ,134 may extend thereabout and :.be soldered thereto. The endcaps are veach provided witha recess 11:1 innwhich .ispositioned afspringcontact clip ri which 4latter .fare secured to vthe .end caps by meanstof; the. drive -sc-rews lf3 .and l5.

The spring contactclips .lareeach stamped from aleaf or,shee t,;o,f metal, preferably beryllium.copper in .the shapezas shown'whereupon their tmedial Larched sections when positioned within .theurecesses k1 of theendcaps are prevented from l.rotating Ytherein and vthe .drive screws .merely .ffasten the clips ito :the end caps.

`The .outer free ends. .offeach .clip iare bent up.-

wardly and outwardly providing a pair of yspaced contact :points which freely ride upon .the contact terminals L9 of 1.a :cartridge rinse. `The nbre. cylindrical casngrlmponqwhich ar e; mounted f the contact .terminals hailing Ia. standard ...external .diameter according :to the ,size of the cartridge fuse and the .indicator casingis 1retainedithereuponsby afsinglefattaching 4clpfl l.

Each attaching clip 2l is preferably stamped from a sheet of beryllium copper having an arched shaped medial section 22 attached to the tube 4 by means of a rivet 23 extending through an opening 24 formed therein. The free ends or arms 25 of each clip are bent and formed at a radius equal to the external diameter of the casing 20 of the particular fuse to which the section 22 allows for the increased diameter of the contact terminals I9 over that of the fuse casing 2U so as to permit the spring contact clips I8 to rest upon the contact terminals I9. However, the single spring attaching clip 2| being connected equidistant from the ends of the lamp housing effects a pressure upon the clips I8 as to cause a binding contact between the clips I8 and the contact terminals I9 of the fuse, whereas the spring clips I8 being positioned at the opposite ends of the lamp housing exert a pull upon the attaching clip which causes the latter to frictionally engage the casing 2B of the fuse thereby preventing the indicator or lamp housing from freely turning upon the attached fuse casing. However, the indicator casing may be manually moved about the circumference of the fuse so that the lamp housing may be positioned at the side of a fuse or at the angle as is best shown in Fig. 5 to avoid the heads of the attaching screws usually provided and extending from the contact terminals I9 of a knife-blade type cartridge fuse. Owing to the length of the arms 25 of the attaching clips the indicator casing may be positioned at either side of a ferrule type cartridge fuse as the contact clips I8 may rest upon and contact with the outer face of the fuse retaining'clips 26 as shown in Fig. 3 of the drawings.

The ferrule type cartridge fuse as shown in Fig. 1 of the drawings is of the 0-30 ampere size which have a standard length of two inches and casing of 1/2 inch in diameter. The radius of the arms 25 of the attaching clip for this particular fuse should be 1/2 inch or equal to the diameter of the fuse casing 20. The length of the tube 4 should be such as to prevent the end caps 3 from projecting beyond the ends of the fuse. In the manufacture of indicators for small size fuses, such as the standard midget fuse the length of the tube 4 should be reduced f and the radius of the arm 25 of its attaching clip should also be reduced to the outside diameter of the casing of the midget size fuse. Like- Wise the length of the tube 4 must be increased and the radius of the arms 25 must be increased f for each larger size fuse in order that the contact clips I8 may engage the terminals IS thereof and the attaching clip 2I extend about the casing 20 thereon as best shown in Fig. 4 of the drawings.

From this arrangement it is apparent that during the manufacture of indicators for all standard cartridge enclosed fuses it is only necessary to cut the extruded tubes 4 to the proper length and form the arms 25 of the attaching clips to meet the particular size fuse to which it is to be applied Whereas, the remaining parts of the indicator will each be of the same siz design and construction for all the different si: standard cartridge enclosed fuses.

In assembling the several parts of the indicatc the end caps 3 are formed with the contact clip I8 attached thereto and the tube 4 with the at taching clip 2| connected thereto whereupon th lead wire I2 of the resistor may be first soldere. to the drive screw I3. The lamp I is then in serted within the tube 4 and its other lead wirl soldered to the drive screw I5. The end caps i are then inserted within the opened ends of thl tube 4 and the drive screws 9 inserted for connecting the tube and end caps together. The

attaching clip 2| is secured to the tube 4, buI

may be turned or rotated upon the rivet 4 whereupon it may lie fiat when the indicator is not in use to save shipping and packing space.

I claim:

1. A lamp type indicator for cartridge enclosed said end caps, means for electrically connecting the lamp housed within said casing to the inner outer extremities of said arms being spaced apart to provide for the free entrance or removal of a fuse casing therebetweeen.

WILLIAM C. LINTON. REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,793,103 La Mar Feb. 17, 1931 1,876,426 La Mar Sept. 6, 1932 2,074,921 Kauffman Mar. 23, 1937 2,164,658 Lyon July 4, 1939 

